Ao Smith 100112851 Hot Surface Ignitor for Gas Water Heaters and Boilers

Product Description

The AO Smith 100112851 Hot Surface Ignitor is a direct-replacement ignition component designed for gas-fired water heaters and boilers. It is manufactured to meet original equipment specifications, making it a reliable choice for HVAC technicians, plumbers, and heating system service professionals who need a dependable part that installs correctly the first time. Hot surface ignitors work by passing an electrical current through a resistive ceramic element. The element heats rapidly to a temperature high enough to ignite the gas burner without requiring a standing pilot flame. This design eliminates the pilot outage issues common in older systems and improves overall system reliability. The AO Smith 100112851 uses a high-density ceramic element with strong heat capacity. It reaches ignition temperature quickly, which reduces startup time and limits the amount of unburned gas that can accumulate during the ignition cycle. Shorter ignition cycles mean safer operation and less wear on downstream components such as the gas valve and control board. This ignitor is used in residential and light commercial heating applications. It is compatible with gas water heaters and hydronic boilers that use hot surface ignition systems. Replacing a worn or cracked ignitor restores proper ignition sequencing and prevents nuisance lockouts that result in no-heat or no-hot-water calls. HVAC service technicians and plumbers stocking service vans will find this part straightforward to install with standard hand tools. The component weighs approximately 0.45 pounds, making it easy to handle during replacement. Keeping a spare on hand reduces callback time and helps close service calls in a single visit.

• Ceramic hot surface element heats quickly to reliable ignition temperature for gas burners
• Direct OEM replacement for AO Smith and Lochinvar gas water heaters and boilers
• Reduces ignition cycle time, limiting unburned gas exposure and improving system safety

Product Highlights

The AO Smith 100112851 Hot Surface Ignitor is a proven OEM-spec replacement part that restores fast, dependable ignition to gas water heaters and boilers. Its ceramic element design and quick heat-up performance make it a go-to choice for trade professionals servicing residential and light commercial heating systems.

Product Information

Standard Information

• Brand: AO SMITH
• Manufacturer Part Number: 100112851

Technical Specifications

• Product Type: Hot Surface Ignitor
• Compatible Equipment: Gas Water Heaters and Boilers
• Element Material: Ceramic
• Weight: 0.45 pounds
• OEM Part Number: 100112851